(1) FIELD OF THE INVENTION
The present invention relates to an apparatus for assembling a wheel attaching unit for use in a vehicle assembly line.
(2) DESCRIPTION OF THE PRIOR ART
With an apparatus of the above-described type for assembling a wheel attaching unit for use in a vehicle assembly line, a pallet mounting thereon a front assembly and a rear assembly is stopped at a setting area, where the front and rear assemblies are set to the body with the body being lowered from above the setting area onto the pallet.
After the above setting operation, the body and the front and rear assemblies are securedly fixed to each other by means of such securing elements as bolt-nuts. Although these securing operations may be carried out at the setting area, it is more common to carry out the same by conveying the pallet further to a securing area provided at a more downstream side in the conveying direction than the setting area.
As is well-known, a wheel-base often differs from one type of vehicle to another. In order to cope with this problem, it is conceivable to provide a plurality of kinds of pallets. That is, it is possible to adapt these pallets to mount the front assembly and the rear assembly with different interdistances respectively.
However, it is very cost-disadvantageous to provide such plurality of pallets for different wheel-bases.
According to further prior art relating to this field (e.g. a Japanese laid-open patent gazette No. 56-103665, a pallet to which a wheel attaching unit is preliminarily set and a vehicle body carried by a further conveyor means are transported in synchronism with each other while the wheel attaching unit is being set to the body from the underside of the pallet.
With this prior-art method which attempts to automatically set the wheel attaching unit to the body from under the pallet, there arises the problem that the synchronized transportations of the pallet and the body must be effected with high precision.